Basket catheter with deformation sensor relying on eddy current

Abstract

A basket catheter and system is configured to determine a force on a basket assembly of the basket catheter and/or determine deformation of the basket assembly by using a sensor assembly in the basket catheter which includes a transmitting coil and multiple receiving coils in the catheter shaft and an electrically conductive plate, disk, or ring at a distal end of the basket assembly. The system is configured to provide signals to the transmitting coil to generate a first magnetic field that in turn causes eddy currents in the electrically conductive plate, disk, or ring, that in turn generates a second magnetic field. The receiving coils detect a superposition of the first and second magnetic fields, and the system determines the force and/or deformation based at least in part on the signals from the receiving coils.

What is claimed is: 
     
         1 . A medical probe comprising:
 a shaft extending along a longitudinal axis;   a plurality of spines extending from a distal end of the shaft and configured to expand away from the longitudinal axis to form a resilient basket;   one or more electrodes coupled to each spine of the plurality of spines;   a transmitting coil disposed within the shaft, aligned along the longitudinal axis and configured to generate a first alternating magnetic field;   a location element coupled to distal ends of the spines, configured to move in relation to the transmitting coil in response to a force on the resilient basket, and configured to generate a second alternating magnetic field based at least in part on the first alternating magnetic field and based in part on a position of the location element in relation to the transmitting coil; and   a plurality of receiving coils disposed within the shaft and configured to output a respective electrical signal based at least in part on a superposition of the first alternating magnetic field and the second alternating magnetic field.   
     
     
         2 . The medical probe of  claim 1 , the location element comprising an electrically conductive, non-ferromagnetic material. 
     
     
         3 . The medical probe of  claim 1 , the transmitting coil and the location element being configured such that the first alternating magnetic field induces eddy currents in the location element and the eddy currents generate the second alternating magnetic field. 
     
     
         4 . The medical probe of  claim 1 , the plurality of receiving coils each being aligned along the longitudinal axis. 
     
     
         5 . The medical probe of  claim 1 , the plurality of receiving coils comprising three receiving coils disposed symmetrically about the longitudinal axis, wherein at least a portion of the plurality of receiving coils is circumscribed by the transmitting coil. 
     
     
         6 . The medical probe of  claim 1 , further comprising:
 a three-axis sensor disposed within the shaft and configured to output signals indicative of a position and orientation of the three-axis sensor relative to a magnetic field generated externally from the medical probe.   
     
     
         7 . The medical probe of  claim 1 , the one or more electrodes configured to sense intracardiac electrogram signals, provide radio frequency signals to ablate tissue, and/or provide at least 900 V between electrodes to ablate tissue with irreversible electroporation. 
     
     
         8 . A medical system comprising:
 a signal generator configured to provide an output signal to a transmitting coil disposed in a shaft of a medical probe; and   a signal processor configured to:
 receive a plurality of input signals from a plurality of receiving coils disposed in the shaft of a multi-electrode basket catheter, and 
 determine a position of an electrically conductive, non-ferromagnetic element coupled to distal ends of spines of the multi-electrode basket catheter based at least in part on a comparison of the output signal to the plurality of input signals. 
   
     
     
         9 . The medical system of  claim 8 , the multi-electrode basket catheter being configured such that the output signal generates a first alternating magnetic field by the transmitting coil, the first alternating magnetic field induces eddy currents in the electrically conductive, non-ferromagnetic element, the eddy currents generate a second alternating magnetic field, and a superposition of the first alternating magnetic field and the second alternating magnetic field affects the plurality of input signals. 
     
     
         10 . The medical system of  claim 8 , the signal processor further being configured to:
 determine a direction and magnitude of a force applied to spines of the multi-electrode basket catheter based at least in part on a comparison of the output signal to the plurality of input signals.   
     
     
         11 . The medical system of  claim 8 , the signal processor further being configured to:
 determine a deformed shape of the spines of the multi-electrode basket catheter based at least in part on a comparison of the output signal to the plurality of input signals.   
     
     
         12 . The medical system of  claim 11 , further comprising:
 a visualization module configured to graphically render the deformed shape for display on a display device and graphically render the deformed shape in relation to an anatomical map.   
     
     
         13 . The medical system of  claim 8 , further comprising:
 an intracardiac electrogram (IEGM) sensor configured to receive IEGM signals from electrodes of the multi-electrode basket catheter.   
     
     
         14 . The medical system of  claim 8 , further comprising:
 an ablation energy generator configured to provide RF signals and/or pulsed signals to electrodes of the multi-electrode basket catheter to perform RF ablation and/or irreversible electroporation of tissue.   
     
     
         15 . A method comprising:
 generating a first alternating magnetic field from a transmitting coil disposed in a shaft of a multi-electrode basket catheter;   inducing eddy currents on an electrically conductive, non-ferromagnetic element coupled to distal spine ends of a basket assembly of the multi-electrode basket catheter;   inducing respective electrical signals in a plurality of receiving coils disposed in the shaft of the multi-electrode basket catheter such that the respective electrical signals are based at least in part on a superposition of the first alternating magnetic field and a second alternating magnetic field generated by the eddy currents; and   determining a position of the electrically conductive, non-ferromagnetic element based at least in part on the respective electrical signals.   
     
     
         16 . The method of  claim 15 , further comprising:
 determining a direction and magnitude of a force applied to basket assembly based at least in part on the respective electrical signals.   
     
     
         17 . The method of  claim 15 , further comprising:
 determining a deformed shape of the basket assembly based at least in part on the respective electrical signals.   
     
     
         18 . The method of  claim 17 , further comprising:
 graphically rendering the deformed shape in relation to an anatomical map.   
     
     
         19 . The method of  claim 15 , further comprising:
 receiving intracardiac electrogram signals from electrodes of the multi-electrode basket catheter.   
     
     
         20 . The method of  claim 15 , further comprising:
 generating radio frequency ablation energy at electrodes of the multi-electrode basket catheter and/or generating pulse-field ablation energy at electrodes of the multi-electrode basket catheter.